The semifinal between Roger Federer and breakout Hyeon Chung had little chance of being a close match, something like dropping a tired, brave guppy into the mouth of a shark and hoping something interesting might happen. Due in part to Chung’s blisters—built up over two weeks of tough matches and plenty of his characteristic, skidding, high-friction footwork over the hard court—it ended up no match at all.

Federer broke serve three times in the first set to pocket it 6-1. Then broke again in the second. At 4-1, Chung got a medical timeout to have his left foot examined. If the young Korean was to have any chance, his movement would have had to hold up. He does not yet have the offensive weapons to compensate for the slightest downtick in his scrambling; his massive legs can’t do the work they’re so good at if they’re sitting atop dead feet. Federer, smelling weakness and wanting to save as much time as possible, was content to blow him off the court. He won 16 of 17 points on his first serve and hit 24 winners to 15 unforced errors. When he knew it was effectively over, he was trying things audacious even by his own standards, serve-and-volley off the second serve. He seemed eager to get his beauty sleep before the final. At 5-2, 30-30, with just over an hour on the clock, Chung retired.

Underneath Chung’s foot was a hellscape his agent described as “blister under blister under blister”—look at the picture that the player later posted, if you want to see what was lurking underneath the wrapping. The NYT’s Christopher Clarey offered more agonizing detail on how Chung had been coping with his feet issues throughout the tournament:

[Coach Neville] Godwin said that when Chung arrived in Melbourne, he held up well for the first week, but that he required anesthetizing injections in both feet before each of his last three matches. At this stage, he essentially had open wounds that were wrapped for play.

“These are serious injections,” [coach Neville] Godwin said. “Each one lasts like a minute. The guy is biting into a towel for a minute, and you have to do it pretty close to match time otherwise it wears off. So 45 minutes before a match, and he’s biting into a towel having someone jabbing his feet.”

Not so bad a run for a low-profile 21-year-old who had been playing on open wounds. Chung, who had until now never cleared the third round of a Slam, has the rest of his career to work on his pedicure game, beef up his serve—currently the most glaring weakness—and add a little more pop and placement to his groundstrokes to spare him the endless grind sessions that birth blisters in the first place. Fortunately for his newfound legion of fans, Chung is more than equipped to fix what’s not working: He is 6-foot-2 and strong enough to find a more authoritative delivery, and he is a rigorous ball-striker who can learn to be more ambitious with where he strikes it. Based on this tournament, Chung will be a fascinating player to watch through the rest of the hard court season and the decade ahead.

It feels almost perverse to say, but you could probably apply the exact same sentence to 36-year-old Roger Federer. He has not lost a set in Melbourne and will now compete for his record 20th Grand Slam title against Marin Cilic, whom he played in the last Wimbledon final, when Cilic was weeping with blisters of his own. Federer won that in straight sets that made you want to avert your gaze, then beat Cilic again later that year in London to solidify a 8-1 head-to-head. Cilic is huge, powerful, and smooth-moving, with no apparent weaknesses to his game. That’s not enough, though. The bar is higher than that, has been higher for years now. This weekend the Croatian will try to do what so many of his generation and failed to do: try to sneak a Grand Slam in while Roger Federer still walks the earth. I can’t believe people cover this person for their entire careers; I’ve been attempting it for a year now and I’m all out of words.